Electric light-flash-producing system



Aug. 16, 1949.-

I E. EDGERTON 3 Sheets-Sheet 1 Fil ed Feb. 11, 1946 Aug. 1949-. H. EDGERTON. 2,478,908

ELECTRIC LIGHT-FLASH-PRODUCING SYSTEM Filed Feb. 11, 1946 3 Sheets-Sheet 2 HAROLD E. EDGEI-ZTO/V, INVENTOR.

BY J

Aug. 16, 1949. H. E. EDGERTON ELECTRIC LIGHT-FLASH-PRODUCING SYSTEM 3 Sheets-Sheet 3 Filed Feb. 11, 1946 HAROLD E. EDGERTDM INVENTOR.

mat ed is. 1.4.:

- UNITED "srArs anaemic uenrr-nssn-rnonuomo srs'rm E ma. Edger-ton, mm; Application February 11, loss, at. 04am.

The present invention relates to electric Systems, and more particularly to flash-producers.

cum. (oi. 111-429) I From a more. speciflc aspect, the invention relates to flash-producing beacons, such as are used at airflelds to signal or otherwise attract the attention of aviators in airplanes. Theinvention is in the nature of an improvement upon the system disclosed in a copending application, Serial No. 510,984, filed November 19, 1943, now Patent No. 2,449,063, of September 14, 1948;

In the said application, there is disclosed beacon employing a number of flash-lamps, ar-

ranged according to a predetermined configuration, and illuminated rapidly, in predetermined sequence or succession, bydischarging a hightion; Fig. 2 is a fragmentary perspective, with parts broken away; Fig. Sis a view clone or the flash-lamps, the reflector in which it is mounted being shown in lon'gitu'dinaLsection; Fig. 4 is a diagrammatic view of circuits and apparatus emb yi the invention, in preferred form; and Fig. 5 is a similar viewof a modification.

Accordingto the speclflc embodiments of the invention that are herein illustrated and de-.

scribed,-a number. 01' flash-lamps [8 are spaced to other configurations also. In the illustrated tension condenser through them rapidly in pre-" determined sequence or succession. As all the energy of the discharge condenser is thus expended, at any particulartime, in producing a flash, high-intensity flashes are thus produced for very short periods of time. The energy oi! the condenser is replenished by recharging it beforeeach discharge thereof. The numberof flash-lamps is sufliciently large and the flashing is s'ufficiently rapid to give the illusion of a beam configuration, however, the flash-lamps l8 are disposed along a circular row in a horizontal plane, within a housing having .a cylindrical transparent with l3, at the top of a beacon support 8.

' Each flash-lamp is mounted in a reflector 2 5 for at B, may be directed north. The flashes from of light traveling rapidly from flash-lamp to flashlamp followingv the predetermined configuration. There are cases, however, where it is not de-' sirable'to be compelled to discharge the same highetension .lcondenser through all the flashlam ps, even.though this is eflected in predeterneou'sly.

to thepresent invention, the limita- First, the entire beacon will not be extinguished densers allows more time for the charging cycle.

- This may be important when it is desiredto opervation of a beacon embodying the present invenmined sequencepr succession, and not simultathe lamps positioned at C and D may similarly be directed east and west. respectively. Two flash-lamps positioned at E and F, on opposite sides of, and adjacent to, the flash-lamp positioned at A, will direct flashes in corresponding directions: the lamp positioned at E will direct a flash between south and south-east, and the lamp positioned at F'will direct its flash between south and south-west. The lamp positioned at G will produce a flash in a direction between east and south-east, and the lamp positioned at H in a direction between west and south-west. The

in case'of the'i'ailure of one of the flash con-' dern's'erg...v =-Second, the use of separate discharge conlamps positioned'at J, K, L and M will send their flashes in directions opposite to the directions of flash'of the lamps positioned at G, E, F and H,-

respectively. As many lamps as desired may be provided, each with a reflector for directing the flash in a particular direction of azimuth. It is convenient to employ also a further flash-lamp, shown positioned at I, for directing its flash upward through a transparent portion 32 of the upper wall 33 of the housing'at the top of the support 8. This lamp is particularly useful in foggy weather. f

Each flash-lamp I8 is of the gaseous-discharge type. The flashes through the separate flashlamps II are produced by discharging therethrough the electric energy stored in separate high-tension dielectric electric-energy-storage means or flash condensers, several of which flash condensers are shown at H, Ill and 2. The

number of separate flash-lamps I8 is equal to the number of separate flash condensers. Each separate condensercorresponds to onefand one only pf the separatefla'sh-lamps, and-each separate flash-lamp corresponds to one and one only of the separate condensers- The condensers constitute the principal sources of energy for efiectlamps I8; they are flrst charged and then discharged through their corresponding flash-lamps is rapidly, in predetermined sequence or succession. Surges of current are thus caused to flow rapidly,in predetermined sequence or succession, through the flash-lamps I9. Each surge of current produces a flash of high intensity in the corresponding flash-lamp I9, followed by prompt extinguishment of that lamp I9 and the flashing of the next flash-lamp I8, in predetermined sequence or succession. Each flash-lamp I8 is thus rendered momentarily luminescent, to produce a flash, by the discharge of its corresponding condenser therethrough.

Assuming, for example, that the flash-lamp positioned at C is the flrst to flash, the next lamp to flash will be that positioned at G, then the lamp positioned at E, then the lamps positioned at A, F, H, D, J, K, B, L and M. The lamp positioned at I will finally be flashed, after which the other lamps will be again flashed in succession, in the same order.

Let it be assumed that the incoming aviator is directly south'of the beacon, and at a considerable distance therefrom. He may, in that event, observe at least the flash from the lamp positioned at A. That single flash alone will guide him to the airport. By reason of the fact that the whole energy of the particular condenser is concentrated, at the time of the flash, in that one lamp, the flash will be of considerable intensity, with the result that he may see it at a very great distance.

As he approaches closer, the flash from the lamp positioned at A will become more intense, and he may begin to see also, though with less intensity, theflashes from the lamps positioned at E and F. As he comes closer still, he may see the flashes of other lamps also, say the lamps positioned at G and H.

The same remarks apply no matter from what direction the aviatorarrives. There will always be at least one lamp flashing along his direction, or nearly so, with the greatest intensity, and perhaps other lamps flashing in slightly different directions with less intensity.

The successive flashing ofthe lamps along different directions of azimuth, moreover, gives the illusion of a rotating beam of light, but without the necessity for employing moving parts. The

, same applies to any other configuration, the nature of the illusion of the beam of light traveling from flash-lamp to flash-lamp depending upon the nature of the configuration.

The preferred gaseous-discharge flash-lamp l8 may contain xenon or other suitable gas. It is shown mounted in an elongated light-permeable glass-bulb jacket or envelope 92, which is shown cemented at 24 to a flat insulating base 94, procathode I and an anode 9, respectively connected to the terminals 6 and I2. A high-voltage-spark trigger or trip wire control starting electrode 22 ing the discharge of their corresponding fiashis connected to the terminal I4.

The voltage to which the condensers I I, II I, 2| I are subjected by the direct-current voltage supply before each discharge thereof is insumcient to cause these condensers to discharge between the cathodes and'the anodes 9 through the normally non-conductive flash-lamps l3, when non-conductive, notwithstanding the connection of the condensers to the flash-lamps I8. The flash-lamps I8 are rendered conductive, however, to control these discharges under the control of the starting electrodes 22. The starting electrodes 22, in turn, may be energized in any desired manner, as bymeans of normally ineffective trigger-discharge circuits operable, when efiective, to render the flash-lamps I8 conductive irrespective of the state of charge of the condensers.

' through a full-wave rectifier I2.

This will now be explained.

In order that it may discharge through its cor--v respondin flash-lamp I8 when conductive, and through no other flash-lamp I8, each discharge condenser is connected to its corresponding flashlamp I8 and its corresponding flash-lamp I8 only. To the attainment of this end, the cathode I and the anode 9 of each flash-lamp I8 are connected through the medium of its terminal pins 6 and I2 across its corresponding discharge condenser and to no other discharge condenser. The terminal pins I2 are connected to a grounded terminal I5, at one side of the respective storage condensers II, I I I, 2I I', by respective conductors 3|, I3I, 23I, through charging resistors 35, I35, -235, and the terminal pins 5 are connected to a terminal I3, at the other side of the condensers, by a common conductor.

The electric-energy-storage condensers may be subjected to a voltage of, say, 2000 volts, from any direct-current supply. The. preferred supply is shown as a transformer 26, the primary winding 28 of which may be connected to any desired source of alternating energy of suitable voltage and frequency, and the secondary winding 30 of which may be connected to each of the condensers This conveniently provides a supply of pulsating current for charging the condensers. The secondary winding 30 mayhave a high impedance for performing ing impedance.

The charging resistors 35, I35,---235, connected, at one side, to the respective terminal pins I2, and, at the other side, to the grounded terminal I5 of the full-wave rectifier I2, serve to isolat the respective discharge condensers II, III,---2II. Thecondensers II, III,---2II are thus connected in parallel to the terminals I3 and I5, at opposite sides of the direct-current energy supply, through their respective isolating charging resistors 35, I35, 235.

A motor 34 is illustrated as the motive power for driving a commutator switch, having as many commutating cams 39, 40, GI, or I39, I40, IBI, as there are flash-lamps I8 to be flashed.

The commutating cam 39 is designed to close' a switch 62, the cam 40 a switch 63, and the cam SI a switch 64. The commutating cams I39, l40,-- IBI are similarly designed to close switches I62, I63, I64. These switches will become momentarily closed, in predetermined sequence or succession, by the corresponding cams, in response to the operation of the motor 2 84, andthen will become reopened. The switches may be of the snap or toggle variety so that they may close with a positive action, to'insure good contact in a short interval of time.

-In the system offFig. 5, condensers 4|, 42, 43 are shown connected in respective trigger-discharge circuits to the terminals I3 and I5, in parallel with the condensers II III, 2I I, by conductors and 51. A resistor 58 is shown connected by the conductors 5| and 51 inseries with the condenser 4|, a resistor 58 in series with the condenser 42, a resistor 60 in series with the condenser 43.

In the system of Fig. 4, however, the corresponding condensers 4| 42, 43 are shown connected by the conductors 5| and 51 across aecmmonimpedance, shown as the portion 8| of a bieeder resistor. One end of the bleeder-resistor portion 8| is connected to the terminal I3, and the other end, through a portion |8| of the bleeder resistor, to the grounded terminal I5. The bieeder-resistor portions BI and I8I are thus connected in series across the direct-current pulsating-energy supply 26, 1 2. The condensers 4|, 42, 43 of Fig. 4 are therefore supplied with voltage, to store electric energy therein, ultimately from the same direct-current-power' supply that -charges the condensers II, III, 2| I. In the system of Fig. 5, the condensers II, III, 2 are all connected to the dlrect current source by way of the terminals I3 and I5. In'the system of Fig. 4, the condensers II, I, 2 are so connected, but the condensers 4| 42, 43 are supplied with voltage from the bieeder resistor 8|, which constitutes their main power supply.

The condensers II, III, 2 may be discharged through their respective discharge tubes I8, as more fully explained hereinafter, by means of the before-mentioned trigger circuits- The motor-driven commutator switch effects a current flow through the separate trigger circuits, in

predetermined sequence, to energize the triggering transformers in succession, thus to energize the trigger electrodes 22 of the flash-lamps I8 in succession. Hight-voltage separate triggering sparks are thus produced to effect a discharge of the respective electric-energy-storage condensers II, III, 2| I through the corresponding luminescent-discharge devices I8, in succession. This is effected through the medium of separate triggering transformers, three of which are shown at 36,

' is connected to the terminal I3 by the conductor 23. The other sides of the secondary winding 38, 48, are respectively connected to the terminals I4 of the triggering starting electrodes 22. A' separate trigger circuit is thus provided for each control electrode 22. g

The connections of the primary windings of the transformers are not the same in the systems of Figs. 4 and 5. Referring first to Fig. 5, the primary winding 14 of the transformer 36 is shown connected across the condenser 4|, in series with the switch 62, by a conductor 8|; the primary winding 41' of the transformer 46 is similarly shown connected across th condenser 42, in series with the switch 63; and the primary winding 54 of the transformer 58 is similarly x shown connected across the condenser 43, in series with the switch 64. Each condenser 4|, 42, 43 is thus connected in its discharge circuit with the primary winding of its transformer. Similar connections to the additional flash -lamps I8, not shown, will be made through similar transformers,

not shown. V

According to the preferred embodiment of the invention shown in Fig. 4, however, the condensers 4| 42, 43 are connected to the respective primary windings 14, 41, 54 by means of triggering circuits comprising normally non-conducting and therefore ineffective, thyratrons or other gaseous-discharge trigger tubes 3|, 1|, I02,

connected in series with the condensers 4 42,

43 and with the primary windings 14, 41, 54. A preferred trigger tube may, be of the coldcathode gaseous-discharge type illustrated and described in Letters Patent 2,185,189, 2,201,166 and 2,201,167, issued to Kenneth J. Germeshausen on January 2 and May 21, 1940. It may comprise an evacuated glass envelope containing several electrodes, namely, a solid cold cathode 2, an anode or plate 5 and one or more control electrodes 3. With I tubes of this type, the current required by the switches I62, I63, I64 becomes negligible, and

wear due to'arcing is thereby reduced, so that long a The discharge circuits of the condenser 4|, 42, I 43 thus contain the respective tubes I, IIIII, I

- I02 and the respective primary windings. These tubes I, IIII, I02 may be operated in succession, in response to the closing of the switches I62, I63 and I64, respectively, as hereinafter more fully described, to discharge through the respective primary windings 13, 41; 54, thereby to flash their respective flash-lamps I8 at the desired instants.

In operation, in the systems of both Figs. 4 and 5, the condenser I I starts to become charged from the direct-current source 26,'12. The tube I is at this time non-conductive. The condenser 4| becomes charged, at the same time, through the resistor 8| and the primary winding 14. In the system of Fig. 4, upon the momentary closing of the switch I62, by the commutator cam I39, the potential ofthe control electrode 3 of the tube becomes raised until the breakdown voltage between the control electrode 3 and the cathode 2 is exceeded, whereupon the trigger tube I becomes conducting. The condenser 4|, which has previously become charged from the rectifier supply 26, 12 of pulsating current, then discharges through the previously-described triggercondenser-discharge circuit comprising the tube I and the primary winding 14. The same discharge of the condenser 4|, through the primary winding 14, takes place in the system of Fig. 5

7 upon the momentary closing of the switch 62 by the commutator cam 39. In both systems, the resulting voltage-surge pulse of the secondary winding 38 of the transformer 36 will thereupon become applied to energize the trigger electrode 22 of the corresponding flash tube I8; this tripping of the trigger-discharge circuit for the condenser 4| will cause the gas in the corresponding flash-lamp I8 to become ionized, producing a conducting path through the corresponding luminescent-discharge device I8, and permitting the condenser II to discharge therethrough, be-

tween the cathode 1 and the anode 9 thereof. The resulting high-voltage discharge through this lamp I8 will produce a very brilliant flash of and the control 7 light of short duration. When the condenser ll becomes ful'y discharged, this lamp I8 becomes extinguished, and the condenser II again becomes charged from the rectifier supply 28, 12 of pulsating current, prior to its next discharge through its flash-lamp l8.

The switch 88 or I88 becomes thereafter momentarily closed, to eflect a similar discharge, in similar manner, of the condenser 42 through the primary winding 41 of the transformer 48. The secondary winding 48 of the transformer 48 will thereupon similarly energize the starting electrode 22 of the next lamp I8 to be flashed. This next lamp I8 will become flashed by the separate condenser III discharging therethrough.

Upon the extinguishment of 'this next lamp I8, the next commutating cam will effect the closing of the next switch; and so on. until the last cam 8i or I8I operates the last switch 84 or I84, whereupon the last condenser 43 will discharge through the primary winding 54 of the transformer 58. The secondary winding 55 will thereupon eifect a discharge of the last condenser 2 through the last lamp I8, thus causing the flashing of this last lamp I8.

The control electrodes 22 will also become energized, in very rapid succession, in this manner, to cause the flash-lamps I8 to become flashed very rapidly in succession, as before described. The flashing cycle will then recommence.

Instead of employing the switches I82, I83, I84, the tubes I, IOI, I02 may be controlled through the medium of well known electrical time-delay circuits for rendering each lamp responsible for starting the succeeding lamp after a predetermined time delay. The, same sequence of flashing can be used for coding the beacon; For example, the flashes could be grouped in numbers that would correspond to those assigned to the particular position. The coding 4 the time spacing of when conductive, each separate condenser cor- -responding to one and one only of the separate flash-lamps and each separate flash-lamp corresponding to one and one only of the separate condensers, means'connecting each condenser to its corresponding flash-lamp and its corresponding flash-lamp only to discharge it through its corresponding flash-lamp when conductive and through no other flash-lamp, means for, charging each condenser, and means for rendering the flash-lamps conductive rapidly in predetermined sequence to discharge the condensers' through their corresponding flash-lamps rapidly in predetermined sequence, thereby to cause the flash-lamps to produce light flashes rapidly in predetermined sequence.

2. A light-flash-producing system having, in combination, a circuit including a, plurality of separate condensers and an equal number of separate normally non-conductive flash-lamps arranged according to a predetermined configuration and each adpated to produce light flashes in response to the discharge of electric energy therethrough when conductive, each separate condenser corresponding to one and one only of the separate flash-lamps and each separate flashlamp corresponding to one and one only of the separate condensers. means connecting each condenser to its corresponding flash-lamp and its corresponding flash-lamp only to discharge it through its corresponding flash-lamp when conductive and through no other flash-lamp, means for charging each condenser, and means for rendering the flash-lamps conductive rapidly in predetermined sequence to discharge the condensers through their corresponding flash-lamps rapidly in predetermined sequence, thereby to cause the flash-lamps to produce light flashes rapidly in predetermined sequence, the number of flash-- rate normally non-conductive flash-lamps arranged according to a predetermined configuration and each adapted to produce light flashes in response to the discharge of electric energy therethrough when conductive, each separate condenser corresponding to one and one only of the separate flash-lamps and each separate flash-lamp corresponding to one and one only of the separate condensers, means connecting each condenser to its corresponding flash-lamp and its corresponding flash-lamp only to discharge it through its correspondin flash-lamp when conductive and through no other flash-lamp, means for charging each condenser before each discharge thereof to a voltage insuillcient to cause it to discharge through its corresponding flash-lamp while non-conductive notwithstanding its connection to its corresponding flash-lamp, normally ineffective means operable when effective to render the flash-lamps conductive, and means for rendering the normally ineffective means effective rapidly in predetermined sequence to render the flash-lamps conductive rapidly in predetermined sequence to discharge the condensers through their corresponding flash-lamps rapidly in predetermined sequence, thereby to cause the flashlamps to produce light flashes rapidly in predetermined sequence, the number of flash-lamps beingsufllciently large and the operation of the rendering means bein sufllciently rapid to 'give the illusion of a beam of light traveling rapidly from flash-lamp to flash-lamp following the predetermined configuration.

4. A light-flash-producing system having, in combination, a circuit including a plurality of separate condensers and an equal number of separate normally non-conductive flash-lamps each adapted to produce light flashes in response to the discharge of electric energy therethrough when conductive, each separate condenser corresponding to one and one only of the separate flashlamps and each separate flash-lamp corresponding to one and one only of the separate condensers, means connecting each condenser to its cor- 7 responding flash-lamp and its corresponding flash-lamp only to discharge it through it corresponding flash-lamp when conductive and through no other flash-lamp, means for charging each condenser, trigger-circuit means connected to the flash-lamps, and means for rapidly triggering the trigger-circuit means to render the flashlamps conductive rapidly in predetermined sequence to discharge the condensers through their corresponding flash-lamps rapidly in predetermined sequence, thereby to cause the flash-lamps to produce light flashes rapidly in predetermined sequence.

5. A light-flash-producing system having, in combination, a circuit including a plurality of separate condensers and an equal number of separate normally non-conductive flash-lamps arranged according to a. predetermined configuration each adapted to produce light flashes in response to the discharge of electric energy therethrough when conductive, each separate condenser corresponding to one and ane only of the separate flash-lamps and each separate flash-lamp corresponding to one and one only of the separate condensers, means connecting each condenser to its corresponding flash-lamp and its corresponding flash-lamp only to discharge it through its corresponding flash-lamp when conductive and through no other flash-lamp, means for charging each condenser before each discharge thereof, separate trigger-circuit means connected to the respective flash-lamps, each separate trigger-circuit means corresponding to one and one only of the separate flash-lamps and each separate flash-lamp corresponding to one and one only of the separate trigger-circuit means,

10 means connecting each trigger-circuit means to its corresponding flash-lamp and and its corresponding flash-lamp only to trigger its correspondin flash-lamp and no other flash-lamp, and means for operating the separate triggercircuit means rapidly in predetermined sequence to render the flash-lamps conductive rapidly in predetermined sequence to discharge the condensers through their corresponding flash-lamps rapidly in predetermined sequence, thereby to cause the flash-lamps to produce light flashes rapidly in predetermined sequence, the number of flash-lamps being sufficiently large and the operation of the separate trigger-circuit means being sufliciently rapid to give the illusion of a beam of light traveling rapidly from flash-lamp to flashlamp following the predetermined configuration.

HAROLD E. EDGERTON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date,

1,328,041 Fischer Jan. 13, 1920 2,327,971 Slepian Aug. 24, 1943 2,351,603 Edgerton June 20, 1944 2,355,349 Wheelock et al Aug. 8, 1944 

